fix(FN-2662): honor project model overrides and stabilize tests

packages/pi-claude-cli/src/types/cross-spawn.d.ts

@@ -0,0 +1,7 @@
+declare module "cross-spawn" {
+  const spawn: typeof import("node:child_process").spawn & {
+    sync: typeof import("node:child_process").spawnSync;
+  };
+
+  export default spawn;
+}